Jan. 19, 2011 at 10:30 AM ET
By Stacy Lipson
When Kathleen Neely was a kid, her eyes were a bit different from other people. While the left was blue, the right was green, and it was smaller -- oh, and it looked like it could belong to a cat.
Neely was born with cat eye syndrome, a condition marked in some patients by a congenital defect of the iris called a coloboma, which causes the pupil of that eye to look keyhole-shaped, much like a cat eye.
Statistics from the National Center for Biotechnology Information estimate that cat eye syndrome affects one in every 50,000 to 150,000 live births. It's a chromosomal disorder, meaning it can be passed from mother to child if the mother is a carrier of the disorder.
Dr. Alex Levin, chief of the Wills Eyes Institute at the Pediatric Ophthalmology and Ocular Genetics Service in Philadelphia, says that cat eye syndrome occurs when patients have an extra piece of chromosome 22, creating two extra copies of that particular piece. Having an extra piece of chromosome 22 can cause serious health issues with organs such as the heart and kidney, Levin says. And vision itself might be impaired, if the coloboma affects the optic nerve and retina.
As a child, Neely was teased for her unusual eyes; she remembers her peers called her names like "Cyclops." When she was 30, her right eye was replaced when it started to deteriorate. Today, she has a prosthetic eye.
"I'm in good health," says Neely, now 39 and living in Boulder, Colo. "I consider myself very fortunate."